Abstract Arterial aneurysm rupture has a very high fatality rate. They can be fusiform or saccular in shape and can occur anywhere in the body. Saccular aneurysms (SAs) carry a greater risk of morbidity and mortality because they are more prone to rupture. These aneurysms can be idiopathic, iatrogenic, traumatic, or atherosclerotic in etiology. Regardless of the cause, SAs are highly-lethal and warrant close imaging surveillance and treatment to prevent a fatal rupture. The current standard of medical practice is primarily to treat SAs with minimally- invasive endovascular interventions such as coil embolization. Despite substantial advancements in coil- embolization technology, serious issues remain with current treatments, including difficulty in administration, the possibility of treatment failure, and extreme cost. Coil embolization requires a unique set of highly- specialized skills to navigate them within sub-millimeter micro-catheters to distant sites and require precise deployment within fragile aneurysm sacs. As a result, such cases are very lengthy and expose patients and medical staff to high radiation doses. While technical success of coil embolization may be high when performed by experienced operators, clinical success reaches only 80%, with failures often resulting from recanalization of the aneurysm and persistent flow through the coils in patients with coagulation disorders. In fact, death is 10 times more likely to occur in patients with coagulopathy, even with endovascular coiling. Furthermore, cost of treatment is excessive; coils can cost many thousands of dollars each and a typical case may require 4-8 coils per aneurysm and in some cases many dozens. We hypothesize that by using cutting- edge tissue engineering tools, it may be possible to produce a universal embolization biomaterial that is stable, durable, hemostatic, adhesive, inexpensive, does not rely on coagulation for clinical success, and requires less specialized skills to embolize SAs. This creative, bioengineering approach may reduce procedure time, decrease radiation exposure, and reduce world-wide morbidity and mortality by removing the need for a costly inventory enabling rural and 3rd world country hospitals to access such technology. We aim to develop a minimally invasive biomaterial-based platform to fill aneurysm sacs using groundbreaking shear-thinning biomaterials (STBs) based on our rich preliminary data. We will develop STBs for endovascular delivery through catheters (Aim 1) and refine STB biocompatibility, adhesiveness, and performance in in vitro aneurysm models (Aim 2). Finally, we will test the engineered STBs in porcine aneurysm models (Aim 3) that mimic the structure of aneurysms in humans.